POS0767 GLANDULAR INVOLVEMENT IN PRIMARY SJÖGREN SYNDROME PATIENTS WITH INTERSTITIAL LUNG DISEASE (ILD) ONSET: A SINGLE CENTER CROSS-SECTIONAL STUDY
Authors: G. La Rocca, F. Ferro, G. Fulvio, S. Fonzetti, G. Governato, V. Donati, M. Mosca, C. Baldini
Journal: Annals of the Rheumatic Diseases (2022)

Background Primary Sjögren Syndrome (pSS) is an autoimmune exocrinopathy classically presenting with sicca symptoms. Nonetheless, disease onset with extraglandular manifestations, particularly interstitial lung disease (ILD), is increasingly reported and probably underestimated. However, studies investigating pSS patients presenting with ILD (pSS-ILD) are limited. Objectives Aim of this study was to better characterize the phenotype of pSS patients presenting with ILD in comparison to pSS patients with classical sicca-onset. We especially investigated whether the two groups differed in glandular involvement comparing functional, imaging and histologic findings, as well as patient reported outcome (PRO). Methods Consecutive newly diagnosed pSS patients, all fulfilling the ACR/EULAR 2016 criteria, were included in this cross-sectional study from September 2016 to October 2021. Clinical, serological and histological initial features where compared in pSS-ILD patients and in pSS patients without ILD involvement, diagnosed during the same time period. Presence of ILD at pSS diagnosis was defined based on clinical findings, imaging assessment and pulmonary function tests. In addition to functional tests, a minor salivary gland biopsy was performed in all cases, recording number of foci and GC-like structures and focus score (FS). Salivary glands ultrasonography (SGUS) was graded using the OMERACT semiquantitative scoring system (0-3) based on parenchyma inhomogeneity. PRO including ESSPRI, OHIP and OSSDI were collected. Extraglandular clinical features and biological abnormalities included in the ESSDAI were recorded. Data were presented as mean±SD, or percent frequency as appropriate. Intergroup comparisons were made using the t-test/Mann–Whitney test for continuous variables and Fisher’s exact test for categorical variables. Results We included 178 newly diagnosed pSS patients (F:M=158:20). ILD was the first pSS manifestation in 11 (6%) cases, 8 F and 3 M, with a median time from ILD onset to pSS diagnosis of 2 ± 2 years. At HRCT, the following patterns were observed: NSIP (4/11), UIP (4/11), NSIP+OP (2/11) and LIP (1/11). Dyspnea on exertion or chronic cough were reported by 7/11 (63.6%) patients. In comparison to sicca-onset patients, pSS-ILD patients presented an older age at diagnosis (55±13 vs 70±7, p= 0.001) and a higher ESSDAI (3.9±4.7 vs 12.3±4.3, p=0.001) driven by the pulmonary domain. Regarding glandular involvement, pSS-ILD patients reported milder xeropthalmia (VAS 5.8±3.1 vs 2.8±3.5, p=0.002), and significative lower scores in OSDI (35.6±24.9 vs 15.3±22.9, p=0.04) and OHIP (4.8±4.4 vs 1.4±3.8, p=0.04), despite no significant differences observed between the two groups in ocular tests and unstimulated salivary flow rate. With respect to histology, no significant differences were found in number of foci and GC-like structures, and FS. Notably, there was a trend towards a different distribution of the SGUS OMERACT score in the two groups. Particularly, none of pSS-ILD patients presented OMERACT score 3 in parotid and submandibular glands, in contrast to 26/167 (15.5%) and 18/167 (10.8%) of classic sicca-onset pSS patients respectively. Finally, no significant differences were observed between the two groups with respect to non-pulmonary extraglandular manifestations, serologic features and other biological parameters. Conclusion ILD-onset pSS patients represent an atypical phenotypic subset, with less pronounced sialadenitis sonographic changes in salivary glands, and with sicca symptoms probably overshadowed by the respiratory disease. Disclosure of Interests None declared